Readily detachable electric plug



Oct. 22, 1963 5. w. oAKEs 3,107,962

READILY DETACHABLE ELECTRIC PLUG Filed April 6, 1962 2 sheets-sheet 1 INVENTOR. George W. Oakes y%dw ATTORNEY Oct. 22, 1963 I a w. OAKES 3,107,962

READILY DE-ITACHABLE ELECTRIC PLUG 1 Filed April 6, 1962 2 Sheets-Sheet 2 INVENTOR. George W. Oakes A'I' TO RN EY United dtates Patent 3,167,962 READELY DETACHABLE ELECTRKQ PLUG George W. (Bakes, Crystai City, Mo. Filed Apr. 6, 1962, Ser. No. 555,669 61mins. (Q1. 339-74) This invention relates in general to a readily detachable electrical plug, and more specifically the invention is directed to improvements in a plug of the type disclosed in my United States Patent No. 2,987,692.

An object of this invention is to provide an electrical plug which can be rendered readily attachable and detachable to the electrical terminals of an electrical appliance with a minimum of effort.

Another object is to provide in an expandable plug of the type disclosed in United States Patent No. 2,987,692. with improved actuator means for effecting the operation of the same.

Another object of this invention is to provide a plug housing or casing constructed and arranged so as to minimize the strains imposed on the cord connected thereto in the event the cord is pulled instead of the plug when disengaging the plug from an electrical appliance.

The feature of this invention resides in the provision of a U-shaped fiat spring for maintaining the respective half sections of the plug housing in the operative position.

Another feature resides in the provision that the plug of the instant invention is relatively simple in construction, relatively inexpensive to manufacture, and positive in operation.

Other features and advantages will become more readily apparent when considered in view of the drawings and description in which:

FIG. 1 is a side elevation view of the plug shown in its normal gripping position;

FIG. 2 is a side elevation view of the plug shown in its detachable or disengaging position;

FIG. 3 is a plan view of FIG. 1 partly shown in section;

FIG. 4 is a plan view of FIG. 2;

FIG. 5 is a left end view of FIG. 3;

FIG. 6 is a left end view of FIG. 4 illustrating the plug in its expanded position;

FIG. 7 is a detailed plan view of one-half section of the plug housing disclosing the interior thereof;

FIG. 8 is a detailed plan view of the other half sect-ion of the plug disclosing the interior thereof;

FIG. 9 is a section view taken along line 9-9 of FIG. 1;

FIG. 10 is a section view taken along line lit-10 of FIG. 1;

FIG. 11 is a sectional view taken along line 11-11 of FIG. 2;

FIG. 12 is a detailed perspective view of the U-shaped spring for urging the respective half section of the plug together; and

FIG. 13 is a perspective view of the contact members of the plug.

Referring to the drawings there is shown the improved electrical plug construction 2% of this invention. As shown, the plug 2h comprises a housing formed essentially of a pair of complementary half sections 21 and 22. Each of the half sections 21 and 22 is formed of an electrical insulating material. The two half sections 21 and 22 are each provided in the forward end or leading portion thereof formed with a pair of spaced, parallel, internally disposed, recesses 21A, 21B and 22A, 22B, respectively, for accommodating the electrical contact members 23 and 24. As shown, each of the recesses open to the leading end 25 of the plug. Thus, in the assembed position, the two half sections are joined so that the recesses 21A and 21B, and 22A and 22B cooperate to define 2 a pair of elongated sockets adapted to receive the electrodes of an electrical appliance.

The rear portion of each half section 2.1 and 22, as seen in FIGS. 1 and 2, is provided with a reduced portion 20A which flares outwardly, and in the assembled position thereof defines an opening 26 for receiving the electrical cord '27. Circumscribing the opening, inwardly of the housing is a groove 28.

In accordance with this invention one of the half sections 21 is provided with a transverse extending partition or baiiie 29 which projects inwardly or" the housing. As shown, partition 29 defines the rear end of the recesses 21A and 218. The other half section 22 provided with a similar partition or bafiie 30 which extends transversely of the reduced rear portion thereof adjacent the groove 28. Thus in the assembled position of the respective half sections 21 and 22, as seen in FIG. 9, the relative partitions 29 and 38 are disposed in spaced relationship from one another. Further, each of the partitions 29 and 30 are provided with a projecting ridge portion 29A and 30A, respectively, which projects slightly into the hollow of the other complementing section. Thus, the arrangement is such that the conductors 27A and 27B of cord 27 are required to assume a sinuous repose within the housing, as best seen in FIG. 9 in the assembled position'of the respective half sections. Each of the half sections is provided with a transversely extending rib 31 and 32. Thus, as seen in FIG. 9, the ridges 29A and 30A, and the oppositely disposed ribs 31 and 32 respectively coact to clamp therebetween the respective conductors 27A and 273. Because of the construction described, a firm and positive connection is afforded for the cord in the assembled position of the respective half sections. Consequently, a stress imposed on the cord in pulling the plug can be successfully resisted.

It will be further noted that the coil spring guard 33, which is generally disposed about the end of cord 27, has its leading convolution 33A fitted into the groove 28 defined in the opening 26, as best seen in FIG. 9. Thus with the half sections 21 and 22 secured the spring guard 33 is positively retained within the housing.

Connected in electrical contact to each of the conductors 27A and 27B, and disposed within the recesses of the housing are the spring clip contact members 23* and 24. As shown each clip contact is made of a single piece of inherently springy conducting material, as for example copper. Each contact member 23 and 24 comprises a pair of spring jaw members 34. Each of the jaws 34 is fluted for a portion of its length and has formed at the forward ends 34A thereof with an outwardly curled end portion, and the rear of said contacts are formed with an inwardly oifset rear end 3413 which are joined by a bight 35.

Electrical contact of the respective clips to its conductor 27A and 27B is had by looping the free end of the conductor between the rear end of its respective contact member and a rivet or eyelet 36 is provided to electrically connect the conductor 27A and 27B into electrical contact with its respective clip 23 and 24.

in accordance with this invention the respective jaws 34- of each clip 23 and 24 are normally biased to open position for disestablishing electrical connection, and the jaws 34 are sufficiently resilient so that they may be flexed towards each other for establishing electrical connection in response to the movements of the half sections acting thereon as will he hereinafter described.

As shown in FIG. 3, the opposed peripheral edge portions of the respective half sections, when in assembled position, are disposed in abutting relationship. However, in accordance with this invention the rearwar dly disposed end portion of at least one of the half sections is beveled as at 38 so that the half sections when assembled have a rocking movement with respect to the forward portions of the contacts 23 and 24. Thus, the half sections 21 and '22 serve as levers fulcrurned to each other. If desired either one or both of the respective half sections 21 and 22 may be beveled as at 38 depending on how much relative rocking action is desired between sections 21 and 22.

An important feature of the instant invention resides in a novel means for separately retaining the half sections 21 and 22 of the housing iri complementary and mating relationship to each other, and also for effecting the rocking movement thereof so that the electrical contacts may receive, grip or release the electrodes of an electrical utensil or appliance.

As shown the half sections 21 and 22 are held in assembled postion through the interaction of a pivot pin 4%) which extends transversely of the respective half sections, and a U-slraped spring 4-1 which embraces the front end of the two half sections.

In accordance with this invention the pin 4% extends normal to the plane coincident with the abutting edges of the respective half sections 21 and 22. So as not to interfere with the relative rocking movement of the respective half sections, the hole 42 in each of the respective half sections for receiving the pin 4% is provided with a dieameter which is slightly greater than that of the pin.

For normally biasing the leading or forward end of the respective half sections 21 and 22 in position to maintain the jaws of the contact members in their biased gripping position, a U-shaped spring 41 is provided. Accordingly, each of the half sections '21 and 22 is provided with an external recess 43 for accommodating the respective leg portions 41A and 41B of the spring. As shown in FIGS. 3, 4, 5 and 6 the recess 43 slopes or tapers inwardly toward the front end of the housin According to this invention, the spring 41 is held in place within the recess '43 by a projection or small indentation 44 which is arranged to r'it into a small depression 43A provided at the rear end of the recess 43 accommodating leg portions 41A and 41B. Accordingly, the recess 43 retaining the spring 41 tapers toward the front end of the respective half sections, so as to provide suflicient clearance at the front end of the plug when the half sections 21 and 22 are to be opened or expanded to permit or facilitate the clip contacts 23 and 24- to expand so as to freely receive or release the electrodes of an appliance.

In accordance with this invention improved means are provided to facilitate the rocking action of the respec tive half sections 21 and 22. Accordingly, a pair of actuators 45 are pivoted about pivot pin 4%. As shown, each of the actuators 45 are similarly constructed, and are thus rendered readily interchangeable. The respective actuators 45 comprise a metal stamping or the like. As shown, the actuators 45 are shaped to conform substantially to the outline of the plug, and they are disposed on either side thereof. Each of the actuators 45 is provided with a pair of spaced ear or lug portions 46 which have a hole formed therein. In assembled position the ears 46 of the respective actuators are disposed in overlapping relationship with the holes 46A thereof aligned with the hole 42. in the respective half sections 21 and 22 which make up the housing. Thus the pin 4% serving to hold the half sections '21 and 22 in assembled position further functions as the pivot or fulcrum for the respective actuators 45.

As shown, each of the actuators 45 have an extended portion 4'7 which projects beyond the rear end of plug 20. Also the extended portions 47 of the respective actuators 45 are contoured with a sloping side surface 45A, which are arranged so as to be in camming relationship with the outer surface of the respective plug sections 21 and 22. Thus it will be apparent that when the extended portions 47 of the actuator are pressed together, they in turn will impart a cumming "ction on the rear end of the respective half sections 21 and 22, thereby closing the space defined by affecting the relative rocking action between the respective half sections. When the rear end of the plug or housing is rocked, the forward end of the plug opens or expands as seen in FIG. 6. Since the spring jaws 34A of the respective contacts 23 and 24 are normally biased to their open position, it will be readily apparent that as the forward ends of the respective half sections are rocked apart, the spring jaws biased closed thereby will flex toward their normally open or expanded position. Consequently, the plug may be rendered readily detachable or attachable as the case may be to the electrodes of an electrical appliance.

-When the pressure on the actuator 4-5 is released, the spring 41 tends to return the forward end of the respective half sections defining the plug housing to their normal grip-ping relationship. Consequently, the half sections 21 and 22 under the influence of spring 41 will cause the respective half sections to hex the contacts against their normal bias to position the same into gripping relationship for forceably gripping the electrodes or terminals of an electrical utensil. V

Assisting the action of spring 41 is the guard spring 33.

It will be noted that as the rear portion of the plug is cammed together, there is a tendency for the opening around the groove 28 to be reduced in diameter and thereby compress the lead convolution 33A of spring guard 33. Thus, the compression of lead convolution 33A functions as a spring to assist spring 41 when the forceon actuators 45 is released to return the half sections to their normal operative position.

Obviously, the plug may be electrically engaged with the terminals or eleotrodesof a utensil :or appliance without first manipulating actuators 45. To separate or disconnect the plug from the terminal or electrodes, the actuators 45 are manipulated causing the contact .mem bers 23 and 24- to assume their open position and so release the terminals or electrodes for easy separation of the plug from the utensil or appliance The plug, as shown in the drawings, is preferable for use with utensils having a handle in close proximity to the socket electrodes or prongs above the latter, because the actuator 45 may be manipulated laterally. I

It will be understood that the projecting end portions 47 of the respective actuators 45 may be readily shaped to facilitate gripping thereof. As for example, they may be formed with small holes to provide for finger rests so as to prevent slipping of an operators fingers thereon. Also, the projecting end portions '47 of the respective actuators 45 may be provided with raised, knurled or scored portions so as to provide an anti-slip surface.

While the instant invention has been disclosed with reference to a particular embodiment for practicing the same, it will be appreciated that the invention is not to be taken as limited to all the details thereof as modifica-f tions and variations thereof may be made Without departing from the spirit or scope of the invention;

I claim:

1. A readily detachable electric plug comprising a housing composed of complementary half sections, each of said halt section-s having abutting bearing edge portions constructed and arranged to permit rocking of said half sections relative to each other, a pair of electrical contact members enclosed within said housing, each of saidcontact members including a spring clip having a pair of jaws normally biased opened for disestablishing by said halr" sections into said gripping relationship, a

pin means extending transversely of said half sections for maintaining said half sections in cooperabl-e assembled relationship, spring means for maintaining said half 7 the bevel at 38 and thereby sections in normal gripping relationship, and a pair of actuators pivoted about said pin means, each of said actuators being oppositely disposed on either side of said housing, said actuators having portions thereof camrning relationship with each of said half sections whereby movement of said actuators toward each other overcome the force of said spring means, and earns said half sections to effect a lateral rocking thereof and thereby permitting said clip contacts to open to facilitate disengagement of said plug.

2. An electric plug adapted to be detachably connected to the socket electrodes of an electrical appliance comprising a housing composed of a pair of complementary half sections, each of said half sections have complementary recesses formed therein to define spaced longitudinally extending and expandable sockets in one end of said plug, and a circular grooved opening adapted to receive an electric cord in the other end of said plug, each of said half sections having cooperating abutting bearing portions along said one end thereof and a beveled bearing portion along said other end of at least one of said half sections, a pair of contact members fitted in said sockets, each of said contacts including a pair of jaws normally biased opened, but which are operatively yieldable to flex into gripping relationship to each other to establish an electric connection, pin means for maintaining said half sections cooperatively associated, spring means connected to said one end of said plug for normally urging said half sections acting on said jaws together to fiex the same into gripping relationship, and actuator means pivoted about said pin means, said actuator means including a pair or" levers, each of said levers being arcuate in cross-section to define opposed tapering portions disposed camming relationship with each of said half sections whereby pressing of said levers toward each other efiect a rocking movement of said half sections laterally relative to the movement of said actuators thereby permitting said sockets to expand and causing said jaw to assume their normally biased opened position to facilitate the disengagement of the plug.

3. An electric plug adapted to be detachably connected to the electrodes of an electrical appliance comprising a housing composed of a pair of complementary half sections, each of said half sections having complementary recesses formed therein to define a pair of spaced longitudinally extending and expandable sockets in one end of said plug, and a grooved opening defined in the other end or" said plug, each of said half sections having cooperating abutting bearing edge portions along said one end thereof and a beveled bearing pontion along said other end of at least one of said half sections, an electrical cord receivable in said opening, a coil spring guard fitted about the end of the cord said guard having one end thereof seated in the groove of said opening, each of said half sections having a transversely extending ridge projecting inwardly of the plug in spaced relationship from one another for gripping the cord within the housing, a pair of contacts enclosed within each of said expandable sockets, each of said contacts including a pair of spring jaws normally biased opened, said jaws being yieidable to fiex into gripping relationship to establish an electric connection, pin means for maintaining said half sections cooperatively associated, a U-shaped flat spring connected to said one end of said plug for normally urging said half sections together to flex said jaws into gripping relationship, and actuator means pivotable about said pin means, said actuator means including a pair of levers fulcrumed about said pin means, each of said levers being arcuate in cross section with opposed portions thereof disposed in camming relationship with each of said half sections whereby pressing said lever together effect a rocking movement of said half sections laterally with respect to the actuators thereby permitting said sockets to expand and causing the jaws of the respective contacts to open.

4. The invention as defined in claim 3 wherein each of said half sections is provided with a longitudinally extending external recess formed therein for receiving the leg portions of said U-shaped spring, and said external recess tapering inwardly to the end of the plug.

5. An electric plug adapted to be detachably connected to the electrodes of an electrical appliance comprising a housing composed of a pair of complementary half sections having expandable sockets formed in one end of said plug and an opening defined in the other end of said plug for receiving an electrical cord, each of said half sections having cooperating abutting bearing portions along the edge thereof and a beveled bearing portion along at least a portion of one of said half sections, each of said half sections having transversely extending bafile means projecting inwardly of the plug in spaced relationship from one another for gripping the cord within the housing, a pair of contacts enclosed within each of said expandable sockets, each of said contacts including a,

pair of spring jaws normally biased opened, said jaws being yieldable to flex into gripping relationship to establish an electric connection, pin means for maintaining said half sections cooperatively associated, a U-shaped fiat spring connected to said one end of said plug for normally urging said half sections together to flex said jaws into gripping relationship, and actuator means pivotahle about said pin means, said actuator means including a pair of levers fu-lcrumed about said pin means, each of said levers being arcuate in cross section with opposed portions thereof disposed in cannning relationship with each of said half sections whereby pressing said lever together efiect a rocking movement of said half sections laterally with respect to the movement of said actuators thereby permitting said sockets to expand and causing said jaws of the respective contacts to open.

No references cited. 

5. AN ELECTRIC PLUG ADAPTED TO BE DETACHABLY CONNECTED TO THE ELECTRODES OF AN ELECTRICAL APPLIANCE COMPRISING A HOUSING COMPOSED OF A PAIR OF COMPLEMENTARY HALF SECTION HAVING EXPANDABLE SOCKETS FORMED IN ONE END OF SAID PLUG AND AN OPENING DEFINED IN THE OTHER END OF SAID PLUG FOR RECEIVING AN ELECTRICAL CORD, EACH OF SAID HALF SECTIONS HAVING COOPERATING ABUTTING BEARING PORTIONS ALONG THE EDGE THEREOF AND A BEVELED BEARING PORTION ALONG AT LEAST A PORTION OF ONE OF SAID HALF SECTIONS, EACH OF SAID HALF SECTIONS HAVING TRANSVERSELY EXTENDING BAFFLE MEANS PROJECTING INWARDLY OF THE PLUG IN SPACED RELATIONSHIP FROM ONE ANOTHER FOR GRIPPING THE CORD WITHIN THE HOUSING, A PAIR OF CONTACTS ENCLOSED WITHIN EACH OF SAID EXPANDABLE SOCKETS, EACH OF SAID CONTACTS INCLUDING A PAIR OF SPRING JAWS NORMALLY BIASED OPENED, SAID JAWS BEING YIELDABLE TO FLEX INTO GRIPPING RELATIONSHIP TO ESTABLISH AN ELECTRIC CONNECTION, PIN MEANS FOR MAINTAINING SAID HALF SECTIONS COOPERATIVELY ASSOCIATED, A U-SHAPED FLAT SPRING CONNECTED TO SAID ONE END OF SAID PLUG FOR NORMALLY URGING SAID HALF SECTIONS TOGETHER TO FLEX SAID JAWS INTO GRIPPING RELATIONSHIP, AND ACTUATOR MEANS PIVOTABLE ABOUT SAID PIN MEANS, SAID ACTUATOR MEANS INCLUDING A PAIR OF LEVERS FULCRUMED ABOUT SAID PIN MEANS, EACH OF SAID LEVERS BEING ARCUATE IN CROSS SECTION WITH OPPOSED PORTIONS THEREOF DISPOSED IN CAMMING RELATIONSHIP WITH EACH OF SAID HALF SECTIONS WHEREBY PRESSING SAID LEVER TOGETHER EFFECT A ROCKING MOVEMENT OF SAID HALF SECTIONS LATERALLY WITH RESPECT TO THE MOVEMENT OF SAID ACTUATORS THEREBY PERMITTING SAID SOCKETS TO EXPAND AND CAUSING SAID JAWS OF THE RESPECTIVE CONTACTS TO OPEN. 